Quiz: Subordinates Problem

Subordinates: Count nodes below each node in a rooted tree. Node $v$ has children with subordinate counts $4$, $2$, $0$. What's $v$'s subordinate count?

1. A.$3$ (count of children)
2. B.$6$ (sum of children's counts)
3. C.$9$ (sum of counts plus children themselves)
4. D.$10$ (plus $v$ itself)